diff --git a/frappe/commands/testing.py b/frappe/commands/testing.py
index bc16e3a337..20c5ab2a48 100644
--- a/frappe/commands/testing.py
+++ b/frappe/commands/testing.py
@@ -102,7 +102,7 @@ def main(
 
 		if doctype or doctype_list_path:
 			doctype = _load_doctype_list(doctype_list_path) if doctype_list_path else doctype
-			discover_doctype_tests(doctype, runner, force, app)
+			discover_doctype_tests(doctype, runner, app, force)
 		elif module_def:
 			_run_module_def_tests(app, module_def, runner, force)
 		elif module:
@@ -197,7 +197,7 @@ def _run_module_def_tests(app, module_def, runner: "TestRunner", force) -> "Test
 	from frappe.testing import discover_doctype_tests
 
 	doctypes = _get_doctypes_for_module_def(app, module_def)
-	return discover_doctype_tests(doctypes, runner, force, app)
+	return discover_doctype_tests(doctypes, runner, app, force)
 
 
 def _get_doctypes_for_module_def(app, module_def):
diff --git a/frappe/testing/discovery.py b/frappe/testing/discovery.py
index 257a6d34e7..c5966cdab7 100644
--- a/frappe/testing/discovery.py
+++ b/frappe/testing/discovery.py
@@ -74,6 +74,7 @@ def discover_doctype_tests(doctypes: list[str], runner, app: str, force: bool =
 	"""Discover tests for the specified doctype(s)"""
 	if isinstance(doctypes, str):
 		doctypes = [doctypes]
+	_app = app
 	for doctype in doctypes:
 		try:
 			module = frappe.db.get_value("DocType", doctype, "module")
@@ -82,13 +83,15 @@ def discover_doctype_tests(doctypes: list[str], runner, app: str, force: bool =
 
 			# Check if the DocType belongs to the specified app
 			doctype_app = frappe.db.get_value("Module Def", module, "app_name")
-			if app and doctype_app != app:
-				raise TestRunnerError(f"DocType {doctype} does not belong to app {app}")
-			elif not app:
-				app = doctype_app
+			if app is None:
+				_app = doctype_app
+			elif doctype_app != app:
+				raise TestRunnerError(
+					f"Mismatch between specified app '{app}' and doctype app '{doctype_app}'"
+				)
 			test_module = frappe.modules.utils.get_module_name(doctype, module, "test_")
 			force and frappe.db.delete(doctype)
-			_add_module_tests(runner, app, test_module)
+			_add_module_tests(runner, _app, test_module)
 		except Exception as e:
 			logger.error(f"Error discovering tests for {doctype}: {e!s}")
 			raise TestRunnerError(f"Failed to discover tests for {doctype}: {e!s}") from e
@@ -100,9 +103,15 @@ def discover_module_tests(modules: list[str], runner, app: str) -> "TestRunner":
 	"""Discover tests for the specified test module"""
 	if isinstance(modules, str):
 		modules = [modules]
+	_app = app
 	try:
 		for module in modules:
-			_add_module_tests(runner, app, module)
+			module_app = module.split(".")[0]
+			if app is None:
+				_app = module_app
+			elif app != module_app:
+				raise TestRunnerError(f"Mismatch between specified app '{app}' and module app '{module_app}'")
+			_add_module_tests(runner, _app, module)
 	except Exception as e:
 		logger.error(f"Error discovering tests for {module}: {e!s}")
 		raise TestRunnerError(f"Failed to discover tests for {module}: {e!s}") from e
diff --git a/frappe/testing/environment.py b/frappe/testing/environment.py
index a8698a8e5b..4eee93d710 100644
--- a/frappe/testing/environment.py
+++ b/frappe/testing/environment.py
@@ -96,7 +96,7 @@ class IntegrationTestPreparation:
 		"""Run 'before_tests' hooks"""
 		logger.info(f'Running "before_tests" hooks for {category} tests on app: {app}')
 		for hook_function in frappe.get_hooks("before_tests", app_name=app):
-			logger.info('Running "before_tests" hook function {hook_function}')
+			logger.info(f'Running "before_tests" hook function {hook_function}')
 			frappe.get_attr(hook_function)()
 
 	@staticmethod